They have been around for several years and more are being installed, especially since the Land Transport Safety Authority's research showing that there has been a 19 per cent reduction in crashes on streets where painted medians have been installed. Rear end crashes have reduced by 66% and pedestrian crashes by 30%. Painted medians are white parallel lines with diagonal lines marked inside.

They have several purposes:

• They provide a wider separation between traffic streams on either side of the road
• They provide drivers with a refuge when they turn into, and out of, side roads
• They give pedestrians a place to pause while crossing two traffic streams.

"Painted medians are used for drivers to slow down before turning right and to wait before moving into a gap in the traffic flow.

"They should not be used as a passing lane or for parking," says Christchurch Road Safety Co- ordinator Susan Cambridge.

When making a right turn in a road with a painted median, indicate then move onto the median. Drivers turning into a road with a painted median may use the median as a refuge before merging into traffic on their left.

Drivers should watch out for pedestrians who may be using the median as a refuge in the middle of the road. They should also watch for oncoming vehicles wanting to use the median, and any raised pedestrian islands.